Electrical fuel feed control



Nov. 24, 1953 J. w. MILLER 2,660,196

ELECTRICAL FUEL FEED CONTROL Filed March 29, 1946 J h WMiller- Fl o 7NVENTOR.

ATTORNEY Patented Nov. 2 4, 1953 FICE ELECTRICAL FUEL FEED CONTROL John W. Miller, Lansing,

Mich, assignor to Motor Wheel Corporation, Lansing, Mich., a

corporation of Michigan Application March 29, 1946, Serial No. 658,134

2 Claims.

This invention relates to fuel feed control devices of a character suitable for use with oil burners of the vaporizing pot type.

The present application is a continuation in part of my copending application Serial No. 414,409, filed October 10, 1941 now abandoned, which application is a division of my application Serial No. 223,181, filed August 5, 1938 now abandoned.

The principal object of this invention is the provision of a fuel feed control device including following specification when read in connection N with the accompanying drawings, wherein:

Figure 1 is a sectional View of the fuel feed control mechanism;

Figure 2 is a schematic illustration of the electrical circuit employed for operating the feed control mechanism; and

Figure 3 is a fragmentary sectional view of a modified form of the invention.

The structure shown in Figure 1 includes a housing 3 having a bottom wall 53 and a top wall It upon which is mounted a cover I I. The housing is formed to provide a fuel supply chamber it! having an inlet opening l3 and an outlet opening it. Fuel is supplied to the chamber I? through a supply pipe 55 connected to any suitable source of supply, not shown. Fuel is discharged from the supply chamber [2 by gravity through a discharge pipe It. A conventional float and needle valve assembly it serves in a well known manner to maintain a substantially constant level of fuel within the chamber [2.

The outflow of fuel through the outlet opening is is regulated by a metering valv i 8. Valve it has its lower end inserted in the outlet opening it and is so mounted as to be moved vertically. The lower end of the metering valve [8 is slotted at it to provide for the passage of fuel. That is to say, the opening for the passage of fuel is defined by the sides and top edges of the slot is and the top surface 23 of the annulus 2 surrounding outlet opening I 4. The size of the opening thus formed may be varied by moving the metering valve [8 up or down.

A collar 2! is threaded on to the metering valve 18 whereby the collar may be adjusted axially of the valve. Normally it is so arranged that when the collar 2! rests against the upper surface of guide bracket 22, the fuel opening through slot is is substantially closed. Another collar 23 is also threaded on the valve [8 somewhat above the collar 2l. Still another collar Ed is threaded on valve l8 adjacent its upper end.

An adjustable set screw 25 is threaded into a bushing 26 on a supporting bracket 33 directly above the upper end of the metering valve l8, providing a stop for the upward movement of the metering valve.

An electro-magnet 21 of conventional closed circuit construction is mounted on bracket 33. A metallic arm 28, comprising the armature, is secured by means of a flexible strip 29 to the electro-magnet whereby the arm may move up or down in response to the energization of the magnet. An operating lever 30 is secured to the under surface of arm 28 by means including a spring 3!. The free end of lever 38 engages the under surface of the collar 23 whereby when the electromagnet is energized the metering valve E8 is raised against its upper abutment, thereby opening the slot l9 therein. When the current is cut off from the magnet 21 the arm 28, lever as and metering valve is drop by gravity, closing the slot 19.

Pivotally mounted at 32 on a support 33 is a triangular shaped bell crank 34. The upper arm of the bell crank is pivotally connected to a thin metallic strip or stop 36 which is so located that at certain times it is placed between the upper end of metering valve I8 and the set screw 25, as shown in Figure 1, and at other times it is moved from between these two parts. The lower arm 31 of the bell crank it is pivotally connected to a stop 35 which is movable from a position shown in Figure l to a position where it is below the shoulder of the collar 25. The bell crank 34 is rocked about its pivot 32 by means of a conventional open circuit electro-magnet 39, having an armature 39a connected to bell crank 34. Steps 35 and 33 are supported against vertical movement by a depending guide bracket 33a.

In Figure 1 the electro-magnet 39 and associated parts, including the stops 36 and 38, are shown in a position which they occupy when the magnet is tie-energized. When the magnet is energized the armature 39a is raised, rocking bell crank 34 about its pivot 32, withdrawing stop 36 from between the upper end of valve l8 and the lower end of set screw 25; and at the same time moving stop 38 to the right to a position where it will engage the under surface of collar 2 to limit the downward movement of valve I8.

When magnet 39 is de-energized, armature Sea drops by gravity thus rocking the bell crank 34 in a clockwise direction to withdraw stop 33 from engagement with collar 24 and to position stop 35 between the upper end of valve l8 and the lower end of set screw 25, as shown in Figure 1.

Thus, when the electro-magnet 39 is energized the stop 33 serves to limit the downward or closing movement of the valve 18 and when electro-magnet 39 is de-energized stop 35 serves to limit the upward or opening movement of valve 18.

It will be understood, of course, that electromagnet 21 is capable of sufficient movement so as to move valve l8 between its extreme closed position and its extreme open position. When stop 36 is interposed between the upper end of valve [3 and the set screw 25, the spring 3| permits sufiicient movement of the operating lever 35 relative to the armature element 28 to compensate for the difierence in travel between the condition which then exists and the condition which exists when stop 36 is moved to its inoperative position.

The electric circuit utilized for energizing electro-magnets 2'5 and 39 and for controlling the operation of the same is illustrated in Figure 2. This circuit includes a transformer fill) having its primary ll connected to suitable source of electric power, not shown. Terminal 32a of the secondary 42 of the transformer is connected by conductor %3 to one terminal of a thermostat Q4. The other terminal of the thermostat s4 is connected by conductor 45 to one terminal of the electro-magnet 2l. The other terminal of the electro-magnet is connected by conductor 1 to terminal 621) of the secondary 52 of the transformer All.

Terminal 12a of the secondary Q2 of the transformer is also connected by conductors 43 and 4'! to one terminal of the second thermostat 48. The other terminal of the thermostat 48 is connected by conductor 2-9 to one terminal of the electromagnet 39. The other terminal of the electromagnet 39 is connected by a conductor 59 and the conductor 4% to terminal 422) of secondary 42 of the transformer 50.

From the foregoing it will be apparent that electromagnet Zl constitutes an electric motor for moving the valve is between a predetermined closed position and a predetermined opened position under the control of thermostat 4-4; and that electro-magnet 39 constitutes a motor for selectively predetermining the opened and closed positions, under the control of thermostat 138. It will also be apparent that other forms of switches may be employed in place of either or both of the thermostats M and 38, if desired.

Collar 2! may be adjusted on valve 58 so that slot I9 may be either completely closed or only partially closed when the valve is in its lowermost position. For most purposes, as for example, when this control is used with a burner of the vaporizing pot type, collar 2! will be so adjusted that slot is will never be completely closed and thus provide for a minute flow of oil at all times sufficient to maintain a pilot fire. Under such all circumstances it will be apparent that the present control is capable of feeding oil in variable quantities which may be defined in terms of the fire produced thereby as follows:

(a) Pilot fire- -when thermostats 48 and 44 are both open;

(b) Low intermediate fire--when thermostat 48 is closed and thermostat 44 is open;

(0) High intermediate fire-when thermostat 48 is open and thermostat M is closed; and

(d) Maximum fire-when thermostats 44 and 48 are both closed.

The structure shown in Figure 3 is generally the same as that shown in Figure 1. Figure 3 diifers, however, in one important respect. That difference is that the structure shown in Figure 3 omits the stop 36 and its attendant function, as will more fully appear hereinafter.

The form of the invention shown in Figure 3 includes a housing (it? exactly the same as the housing 8 previously described. The housing has a top wall 6! on which a cover 62 is mounted. The housing 69 is provided with a fuel chamber 63 from which the flow of fuel is controlled by means of a vertically movable metering valve B l.

The upper end of the valve as is threaded and receives a pair of collars 65 and 66.

Mounted on the cover 5! over the valve 64 is a. bracket 87. A threaded. bushing 68 is mounted on the bracket 6?. A stop pin 69, which operates as does the stop pin 25 previously described, is threaded through the bushing 68.

The bracket 5'5 also carries an electro-magnet lil which is provided with a metallic arm "H comprising the armature of the electro-magnet. An operating lever 52 is connected to the arm 1! and underlies collar 65 whereby when the electromagnet is energized the metering valve 64 is raised against the stop pin 69 to permit fuel to flow from the fuel chamber 63. When the electro-magnet is de-energized the arm "H and lever 12 permit the valve to drop by gravity.

A bell crank 13 is pivotally mounted at it on a bracket '5?! adjacent to bracket Bl. One arm of the bell crank is connected to an electro-magnet l6 so that the bell crank may be rocked about its pivot. Another arm of the bell crank 73 is pivotally connected to a stop ll which is movable from the position shown in Figure 3 to a position where it is below the collar 66. The stop H is guided in the opening in a guide it attached to bracket 6?.

When the parts of the device are in the position shown in Figure 3, the electro-magnet m is energized to raise the valve 55 against the stop pin 69. In this position the valve is wide open to permit fuel to flow at its maximum rate. When the electro-magnet is deenergized the valve drops by gravity to its pilot position which is adjusted by means of a collar 79 threaded on the valve 64.

If now the electro-magnet '56 is energized it will rock the bell crank 13 about its pivot and force the stop 11 into a position underneath the collar 66. When that occurs the valve 65 cannot close to pilot position. The movement of the valve due to the energization and deenergization of electromagnet 10 will be between wide open, maximum fire, position against stop pin 59, and a low intermediate fire position determined by the stop 11 and collar 65.

It will be evident, of course, that the device shown in Figure 3 will be employed with a circuit the same as that shown in Figure 2. Then, when the device is operating, fuel will be fed to the burner with which the control is associated in variable quantities which may be defined in terms of the fire produced thereby, as follows:

(a) Pilot fire-when the thermostats 48 and 44 are both open;

(12) Maximum fire when the thermostat 44 is closed; and

(0) Low intermediate firewhen thermostat 48 is closed and thermostat 44 is open.

The scope of the invention is indicated in the appended claims.

I claim:

1. A fuel feed control comprising: a liquid fuel supply chamber provided with an outlet opening, an adjustable metering valve associated with said outlet opening; means for moving said valve to regulate the flow of fuel through said outlet opening including an electric motor; and means directly acting on the valve structure for limiting the range of movement of said valve under the influence of said motor including a second electric motor; said means being adapted to limit the movement of the valve in one direction when said second motor is energized and to limit the movement of the valve in the other direction when the second motor is de-energized.

2. A iuel feed control comprising: a liquid fuel supply chamber provided with an outlet opening; an adjustable metering valve associated with said outlet opening; means for moving said valve to regulate the flow of fuel through said outlet opening including an electric motor; and means for limiting the range of movement of said valve under the influence of said motor including a pair of stops and a second electric motor for moving said stops, one of said stops being adapted to limit the movement of the valve in one direction and the other of said stops being adapted to limit the movement of the valve in the other direction.

JOHN W. MILLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,081,693 Parker Dec. 16, 1913 1,508,138 Foote Sept. 9, 1924 1,700,428 Breese Jan. 29, 1929 1,754,868 Wehling Apr. 15, 1930 1,786,878 Van Kenren Dec. 30, 1930 2,145,446 Johnson Jan. 31, 1939 2,187,045 McCorkle Jan. 16, 1940 2,255,917 Donley Sept. 16, 1941 2,273,205 Kommer Feb. 17, 1942 2,329,820 Breese Sept. 21, 1943 2,335,212 Landon Nov. 23, 1943 2,389,754 Baer Nov. 27, 1945 

